We present integral field unit (IFU) spectroscopy and self-consistent photoionisation modelling for a sample of four southern Galactic planetary nebulae (PNe) with supposed weak emission-line (WEL) central stars. The Wide Field Spectrograph (WiFeS) on the ANU 2.3 m telescope has been used to provide IFU spectroscopy for NGC 3211, NGC 5979, My 60, and M 4-2 covering the spectral range of 3400-7000Å. All objects are high excitation non-Type I PNe, with strong He II emission, strong [Ne V] emission, and weak low-excitation lines. They all appear to be predominantly optically-thin nebulae excited by central stars with $T_{\rm eff} > 10^5$K. Three PNe of the sample have central stars which have been previously classified as weak emission-line stars (WELS), and the fourth also shows the characteristic recombination lines of a WELS. However, the spatially-resolved spectroscopy shows that rather than arising in the central star, the C IV and N III recombination line emission is distributed in the nebula, and in some cases concentrated in discrete nebular knots. This may suggest that the WELS classification is spurious, and that, rather, these lines arise from (possibly chemically enriched) pockets of nebular gas. Indeed, from careful background subtraction we were able to identify three of the sample as being hydrogen rich O(H)-Type. We have constructed fully self-consistent photoionization models for each object. This allows us to independently determine the chemical abundances in the nebulae, to provide new model-dependent distance estimates, and to place the central stars on the H-R diagram. All four PNe have similar initial mass ($1.5 < M/M_{\odot} <2.0$) and are at a similar evolutionary stage.
We report the IR properties of planetary nebulae with WR type and $wels$ central stars known to date and compare them with the IR properties of a sample of PNe with H-rich central stars. We use near-, mid- and far-IR photometric data from archives to derive the IR properties of PNe. We have constructed IR colour-colour diagrams of PNe using measurements from $2MASS$, $IRAS$, $WISE$ and $Akari$ bands. [WR] PNe have a larger near-IR emission from the hot dust component and also show a tendency for stronger 12$μ$m emission as compared to the other two groups. Cool AGB dust properties of all PNe a…
On the non-thermal kappa-distributed electrons in planetary nebulae and HII regions: the kappa index and its correlations with other nebular properties
Co-spatial Long-slit UV/Optical Spectra of Ten Galactic Planetary Nebulae with HST/STIS II. Nebular Models, Central Star Properties and He+CNO Synthesis
Wolf-Rayet ([WR]) and weak emission-line ($wels$) central stars of planetary nebulae (PNe) have hydrogen-deficient atmospheres, whose origins are not well understood. In the present study, we have conducted plasma diagnostics and abundance analyses of 18 Galactic PNe surrounding [WR] and $wels$ nuclei, using collisionally excited lines (CELs) and optical recombination lines (ORLs) measured with the Wide Field Spectrograph on the ANU 2.3-m telescope at the Siding Spring Observatory complemented with optical archival data. Our plasma diagnostics imply that the electron densities and temperatures…
Fast highly-collimated outflows including bipolar knots, jet-like features, and point-symmetric filaments or string of knots are common in planetary nebulae (PNe). These features, generally named as jets, are thought to play an active role in the nebular shaping immediately before or at the same time that fast stellar winds and D-type ionization fronts shock and sweep up the nebular envelope. The space velocity, radial distance from the central star and kinematic age of jets in PNe cannot be determined because the inclination anglewith the line-of-sight is usually unknown. Here we have used th…
The Large sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) medium-resolution spectral survey of Galactic Nebulae (MRS-N) has conducted for three years since Sep. 2018 and observed more than 190 thousands nebular spectra and 20 thousands stellar spectra. However, there is not yet a data processing pipeline for nebular data. To significantly improve the accuracy of nebulae classification and their physical parameters, we developed the MRS-N Pipeline. This article presented in detail each data processing step of the MRS-N Pipeline, such as removing cosmic rays, merging single exposure…
The Abundances of Light Neutron-Capture Elements in Planetary Nebulae III. The Impact of New Atomic Data on Nebular Selenium and Krypton Abundance Determinations
Integral field unit (IFU) spectroscopy of planetary nebulae (PNe) provides a plethora of information about their morphologies and ionization structures. An IFU survey of a sample of PNe around hydrogen-deficient stars has been conducted with the Wide Field Spectrograph (WiFeS) on the ANU 2.3-m telescope. In this paper, we present the H$α$ kinematic observations of the PN M2-42 with a weak emission-line star ($wels$), and the compact PNe Hen 3-1333 and Hen 2-113 around Wolf-Rayet ([WR]) stars from this WiFeS survey. We see that the ring and point-symmetric knots previously identified in the vel…
Radio continuum observations trace thermal emission of ionized plasma in planetary nebulae and bring useful information on nebular geometries. A model of homogeneous sphere or shell cannot fit the nebular spectra and brightness temperatures. Two alternative models have been proposed in the literature: the first one consists of two homogeneous components, while the other one is a model of a shell with a significant radial density gradient. On the other side, prolate ellipsoidal shell model can successfully fit the surface brightness distribution of selected objects. We verify the existing model…
The Kinematics of the Permitted C II $λ$ 6578 Line in a Large Sample of Planetary Nebulae
本文介绍了76个行星状星云中83条视线的C II $λ$ 6578允许谱线的高光谱分辨率光谱观测结果，其中大部分是用位于Sierra San Pedro Mártir的国家天文台的2.1m望远镜上的Manchester Echelle摄谱仪获得的。我们研究了C Ⅱ $λ$ 6578允许谱线相对于其它允许谱线和碰撞激发谱线的运动学。统计上，我们发现，运动学的C II $λ$ 6578线是不是那些预期的，如果这条线产生的重组的C $^{2+}$离子或荧光的C $^+$离子在电离平衡中的化学均匀的星云等离子体，但相反，它的运动学是那些适合的体积比预期的更内部。这个样本中的行星状星云具有明确的形态，并且与银河系凸起中的对应物相比，H $α$线宽限制在有限的范围内（没有大的值），这两者都可以解释为年轻星云壳的结果，星云模型也支持这一推论。关于长期存在的化学丰度之间的差异推断允许和碰撞激发的发射线在光电离星云，我们的研究结果意味着，多个等离子体成分通常发生在行星状星云。
The increase in discovered close binary central stars of planetary nebulae is leading to a sufficiently large sample to begin to make broader conclusions about the effect of close binary stars on common envelope evolution and planetary nebula formation. Herein I review some of the recent results and conclusions specifically relating close binary central stars to nebular shaping, common envelope evolution off the red giant branch, and the total binary fraction and double degenerate fraction of central stars. Finally, I use parameters of known binary central stars to explore the relationship bet…
A significant fraction of planetary nebulae (PNe) exhibit collimated outflows, distinct narrow kinematical components with notable velocity shifts with respect to the main nebular shells typically associated with low-ionization compact knots and linear or precessing jet-like features. We present here a spatio-kinematical investigation of a sample of twelve PNe with morphologies in emission lines of low-ionization species suggestive of collimated outflows. Using archival narrow-band images and our own high-dispersion long-slit echelle spectra, we confirm the presence of collimated outflows in H…
3-D modelling of the collimated bipolar outflows of compact planetary nebulae with WR-type central stars
我们提出了高分辨率，长狭缝光谱观测五个紧凑的（$\leq$ 10角秒）行星状星云位于靠近银河系的隆起区域，没有高空间分辨率的图像。这些数据来自圣佩德罗·马尔蒂尔银河系行星状星云运动学目录（López et al. 2012）。其中四个天体（M1 -32、M2 -20、M2 -31和M3 -15）的中心恒星为WR型，第五个天体（M2 -42）的核心为Wels型。这些观测结果揭示了在所有这些存在的密集和厚赤道环面状组件和高速，准直，双极流出。代码SHAPE是用来调查的主要形态运动学特征和再现的3-D结构，这些对象假设一个圆柱形的速度场的双极流出和同源膨胀法的环面/环组件。双极外流的反投影膨胀速度在65至200 km $\rm{s^{-1}}$的范围内，而环面/环组件显示出慢得多的膨胀速度，在15至25 km $\rm{s^{-1}}$的范围内。研究发现，这些行星状星云具有非常相似的结构成分，它们发射谱线的差异主要来自它们在天空中的不同投影。它们的形态运动学特征与WR型核的关系值得进一步研究。
The majority of planetary nebulae (PNe) show axisymmetric morphologies, whose causes are not well understood. In this work, we present spatially resolved kinematic observations of 14 Galactic PNe surrounding Wolf-Rayet ([WR]) and weak emission-line stars ($wels$) based on the H$α$ and [N II] emission taken with the Wide Field Spectrograph on the Australian National University 2.3-m telescope. Velocity-resolved channel maps and position--velocity diagrams, together with archival Hubble Space Telescope ($HST$) and ground-based images, are employed to construct three-dimensional morpho-kinematic …
The kinematics of the nebular shells around low mass progenitors of PNe with low metallicity
我们分析了26个行星状星云（PNe）的内部运动学与低金属丰度，似乎来自最低质量的祖星，包括晕PN人口。基于从圣佩德罗·马蒂尔PNe运动学目录（López et al. 2012）中绘制的空间分辨长缝中阶梯光栅光谱，我们根据迄今为止用于此目的的最大样本测量其全球膨胀速度来表征这些PNe的运动学。我们发现运动学，遵循在其他研究中观察到和预测的趋势，但也发现，大多数的PNe研究在这里往往有膨胀速度小于20公里/秒，在所有考虑的发射线。我们在这个具有低质量祖先的低金属丰度行星状星云样本中观察到的低膨胀速度很可能是微弱的中央星风驱动星云壳运动学的结果。这项研究补充了以前的结果（Pereyra等人，2013年，以及其中的参考文献），这些结果将PN壳的膨胀速度与中心恒星的特征联系起来。
Individual distances to planetary nebulae are of the utmost relevance for our understanding of post-asymptotic giant-branch evolution because they allow a precise determination of stellar and nebular properties. Also, objects with individual distances serve as calibrators for the so-called statistical distances based on secondary nebular properties. With independently known distances, it is possible to check empirically our understanding of the formation and evolution of planetary nebulae as suggested by existing hydrodynamical simulations. We compared the expansion parallaxes that have recent…
我们重新考虑校准行星状星云的统计距离尺度，检查精度和系统误差的各种距离的方法，以及规模本身。一种不同的校准策略，一种基于Harris等人（2007; Benedict等人2009）的精确三角函数的校准策略。大多数统计尺度都有一个整体的尺度误差;此外，所有四个测试显示距离比[尺度/实际]对星云半径的依赖性。然而，Frew的H-alpha标度（2008;在Frew et al. 2014中略有修订）在大R时只有很小的半径依赖性，总体上与这些松弛一致。一些用于校准的方法存在系统误差，并且发现消光法大多不可靠。比较依巴谷的一些大行星与我们的“最佳估计”的距离证实了哈里斯等人发现的高估2.5。我们认为这可能与Melis等人（2014）在测试依巴谷天体的一些昴星团时发现的较小高估有关。
It has recently been noted that there seems to be a strong correlation between planetary nebulae with close binary central stars, and highly enhanced recombination line abundances. We present new deep spectra of seven objects known to have close binary central stars, and find that the heavy element abundances derived from recombination lines exceed those from collisionally excited lines by factors of 5-95, placing several of these nebulae among the most extreme known abundance discrepancies. This study nearly doubles the number of nebulae known to have a binary central star and an extreme abun…
Star-forming regions are often associated with nebulosity. In this study, we investigated infrared diffuse emission in Spitzer IRAC images. The infrared nebula L1527 traces outflows emanating from a low-mass protostar. The nebular color is consistent with the color of a stellar photosphere with large extinction. Nebulae around the HII region W5-East are bright in the infrared. These colors are consistent with the model color of dust containing polycyclic aromatic hydrocarbon (PAH). The strength of ultraviolet irradiation of the nebulae and the small dust fraction were deduced from the infrared…
Context. Gaia Early Data Release 3 (EDR3), published in December 2020, features improved photometry and astrometry over that published in the previous DR2 file, and includes a substantially larger number of sources, of the order of 2,000 million, making it a paradigm of Big data Astronomy. Aims. We demonstrate how Gaia data mining can effectively help to solve the issue of central star misidentification, a problem that has plagued the field since its origin. As we did for DR2, our objective is to present a catalogue of CSPNe with astrometric and photometric information in EDR3. Methods. Gaia G…
